1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Narrow band-pass filter

  1. Mar 3, 2006 #1
    I was aksed to study and draw the transitions of narrow band-pass filter function gives as :

    Av(s)=Ao (s*Wo/Q)*(1/(s^2+s*Wo/Q+Wo^2) ; S Laplace transform

    where: Wo is central frequency

    Q quality factor Q=Wo/WH-WL=Wo/BW

    WH &WL are high cut-off and low cut-off frequency respectively

    just need some hits !

    thanks in advance!
  2. jcsd
  3. Mar 3, 2006 #2
    Whats your problem? Determine the center, upper, and lower cut off frequencies?
  4. Mar 3, 2006 #3


    User Avatar

    Staff: Mentor

    You can use Excel to plot it to get a feel for what it looks like, although it will plot best in log-log (log frequency on horizontal axis). Start with a Q=1 plot, then overlay Q=10 and Q=0.1 plots. Pick some generic Wo frequency for starters, like 100kHz or something.

    What textbook are you using? Most texts should have a good discussion of the BPF transfer function and the effect of the Q factor. If your text is lacking, there are lots of resources on the web. I googled bandpass analog filter transfer function tutorial, and got lots of good hits. Here's one -- scroll down to some of the Filter Design articles:

    http://www.circuitsage.com/filter.html [Broken]
    Last edited by a moderator: May 2, 2017
  5. Mar 3, 2006 #4
    oh ,berkeman thanks you for your googling , sometimes i google for various things but I find out that you have good experience in selecting keywords, is there any generic rule to precisely find what you need through google or that just depends on repitation?!

    thanks a lot!
  6. Mar 3, 2006 #5


    User Avatar

    Staff: Mentor

    Mostly getting better at google involves trying out stuff, and learning some of the advanced features. Check out the advanced feature list sometime -- I forget if google supports the "near" keyword, for example. Only some search engines do. Using quotes around multiple word phrases helps a lot in cutting down on the extra search hits that are displayed. And using the + sign before required terms in the search also helps a lot sometimes.

    Also, I've lately found the keywork "tutorial" to be real helpful in finding info in the form that helps folks here on PF.
  7. Mar 4, 2006 #6
    I didnn't find that feature but there's another feature for finding pages similar to a webpage we detect , and find pages that link to the page!

    Page-Specific Search:
    Similar Find pages similar to the page
    Links Find pages that link to the page
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook